Illuminated pushbutton switches having tandem
lamp impedance devices



Aug. 18, 1970 J. F. WALDORF Re. 26,936

ILLUMINATED PUSHBUT'I'ON SWITCHES HAVING TANDEM LAMP IMPEDANCE DEVIGES 2Sheets-Sheet 1 Original Filed July 24. 1961 l lllllllllllll'""IIHUIHIIll! wwml m k a g. u n K I l 2 F mmml awn/Wm -Bow /Y WM &3;FIX/125.

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Aug. 18, 1970 WALDQRF Re. 26,936

ILLUMINATED PUSHBUTTON SWITCHES HAVING TANDEM LAMP IMPEDANCE DEVICES 2Sheets-Sheet 2 Original Filed July 24. 1961 2: llllll 1...

United States Patent 26,936 ILLUMINATED PUSHBUTTON SWITCHES HAVINGTANDEM LAMP IMPEDANCE DEVICES Joseph F. Waldorf, New Berlin, Wis.,assignor to Cutler- IIammer, Inc., Milwaukee, Wis., a corporation ofDelaware Original No. 3,231,706, dated Jan. 25, 1966, Ser. No. 126,069,July 24, 1961. Application for reissue July 17, 1967, Ser. No. 661,139

Int. Cl. H01h 9/18 US. Cl. 200167 5 Claims Matter enclosed in heavybrackets II] appears in the original patent but forms no part of thisreissue specification; matter printed in italics indicates the additionsmade by reissue.

ABSTRACT OF THE DISCLOSURE An illuminated pushbutton electricalswitching apparatus including tandemly mounted puslzbutton operator,illuminating apparatus including a lamp and transformer block, andcontact block with reciprocating means passing through the transformerblock to provide operating connection between the operator and contactblock.

BACKGROUND OF THE INVENTION This invention relates generally toimpedance type illuminated push button switches. A number of thesesystems are normally controlled from a panel on which the impedance typeilluminated push buttons are mounted to provide an indication of theoperational condition of each of the devices which are controlled fromthe panel.

In order to obtain the most ellicient use of floor space these controlpanels must be limited in area. Illuminated push button switchespresently available have a heavy duty contact block and a lamptransformer mounted on the switch in a side-by-side relation whichrequires a relatively large panel area.

SUMMARY OF THE INVENTION The primary object of this invention is toprovide an improved illuminated push button switch that occupies aminimum of space on a control panel.

This object in a preferred form is accomplished by mounting atransformer and contact block in a tandem relation on the push buttonassembly. Contact blocks such as shown in Nolden et al. Pat. 2,930,859issued March 29, 1960, and owned by the assignee of this invention, areused in combination with a novel transformer. The transformer is mountedbetween the contact block and switch button assembly with any number ofcontact blocks mounted in tandem on the unit without any increase in thepanel area required for the push button assembly. This reduction in thespace required for the push button assemblies has made it possible toincrease the number of buttons on the panel without increasing the sizeof the panel.

Another object of this invention is to provide a lamp transformer thatautomatically compensates for an overload in the circuit.

A further object is to provide an improved push button assembly that iseasy to assemble and can be supplied as an independent unit.

Other objects and advantages will be apparent from the specification andclaims, as will obvious modifications of the two embodiments shown inthe drawings, in which:

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a top view of theilluminated push button switch;

Re. 26,936 Patented Aug. 18, 1970 DESCRIPTION OF THE PREFERREDEMBODIMENT Referring to the drawing, the illuminated push button switchincludes a push button assembly 10 supporting a lamp transformer 14 anda heavy duty electric switch 16 in a tandem relation. The push buttonassembly is mounted on a panel 18 by inserting outer hollow cylindricalhousing 20 through an aperture in the panel and locking the assembly tothe panel by means of a clamping collar 24 threadably mounted on thecylindrical housing.

As shown in FIGS. 3 and 4, the electric switch is of the type describedin the Nolden et al., patent with a rectangular molded housing 26 and apair of depressible operating plungers 28 projecting above the housing.These switches may be either of the single circuit or double circuittype with the double circuit type shown in the drawings and the switchesbeing either normally open or normally closed depending on therequirements of the particular circuit. In the present system switches[20] 30 and 32 (FIG. 6) are both normally open. Screws 34 having athreaded end 36 and a head end 38 that is kerfed, recessed andinternally threaded are positioned in holes molded in section 40 on theside of the housing for securing the contact block to the transformer orto another contact block. A plastic retaining ring 41 may be provided onthe screw to hold its screw on the housing when disassembled.

The transformer also has a rectangular molded housing 42 similar to themolded housing of the contact block with screws 35 provided in holes 44molded in the housing. The transformer is of the double coil type and ismolded into the housing with a primary winding 48 and a secondarywinding 50 wound on a transformer frame 52. This transformer ismagnetically saturated at approximately 150% of rated primary voltageoverload so that the secondary voltage ceases to rise when the primaryvoltage is increased. This type transformer protects the [amps] lampfrom burn-out at primary [votage overoad] voltage overload such asencountered when a volt device is erroneously connected to a 220 voltcircuit. A lamp base 54 projects outward from the transformer housingand supports a lamp socket 56 which has terminals 58 connected to theends of the secondary winding. A pin base type lamp 60 plugs into theterminals in the lamp socket.

The contact block is secured to the transformer by threadably engagingscrews 34 with the head end of screws 35. The switch actuating plungersof the contact block will project into indentations 62 in thetransformer block for engagement by pusher pins 64 freely movable inholes 66 molded in the housing. Retaining rings 68 hold the pins in thehousing. The transformer is secured to the outer housing 20 bythreadably engaging screws 35 in threaded holes 70 in flange 72 of theouter housing. The lamp base will project into the hollow interior ofthe outer housing, with the top of the lamp located at approximately thesame height as the outer housing.

The push button assembly includes a lens holder 74 that has atranslucent plastic lens 76 threadably secured thereto and sealed by afiat washer or O-ring 78. The lens holder is reciprocally movable in theouter housing and has a resilient oil seal 80 in annular groove 82 inthe side of the lens holder to slidably engage the interior surface ofthe outer housing. Flanges 84 on the lens holder engage grooves (notshown) at the lower end of the inner surface of the outer housing toprevent the lens holder from rotating and engage a shoulder (not shown)at the end of the groove to limit the upward travel of the lens holderin the outer housing. A pair of pins 86 extend outward from the bottomof the lens holder and are aligned with the pusher pins in thetransformer. When the lens is pushed the pins will push the pusher pinsagainst the contact block plungers to actuate the switches A compressionspring 90 is positioned in groove 92 in the lens holder and acts againstplate 94 united to the lens holder to bias the holder and lens in theouter position. A gasket 96 is provided between flange 72 and the panelto seal the push button switch in position. A metal washer 98 may beprovided between the clamping collar and the outer surface of the panelif desired.

As seen in FIG. 6, the illuminated push button switch is used to controlthe operation of a motor starter or contactor M which is used to controlthe energization of an electric motor or some other electrical function(not shown). When the lens is depressed, normally open switches 30 and32 will be closed energizing the motor starter M and the primary windingof the transformer. The lamp will light as soon as switch 32 is closed.The motor starter will close normally open relays M and M M closes aholding circuit for the motor starter and M closes a holding circuit forthe primary of the transformer. When the lens is released both switches30 and 32 will be opened and if the light goes out the relays have notbeen closed and the system is not operating. An overload switch 95 and astop switch 97 are also provided in the line to deenergize the system atthe end of an operating cycle.

Where a pretest system is desired a second contact block, shown dottedin FIG. 4, is added to the system with a normally closed switch 99connected in series with relay contacts M When the lens is pushedswitches 30 and 32 will be closed and switch 99 opened. The lamp willlight and the motor starter M will be energized closing the relays. Thelens is released and the lamp should remain lit if the motor starter isoperating. If the light should go out on the panel, the lens can bepushed to determine whether the motor starter has opened the relays orthe lamp has burned out. If the latter, the lamp can be immediatelyreplaced by merely removing the lens from the holder.

Although one embodiment of the present invention has been illustratedand described, it will be apparent to those skilled in the art thatvarious changes and modifications may be made therein without departingfrom the spirit of the invention or from the scope of the appendedclaims.

I claim:

1. An illuminated pushbutton electric switch unit having a switchcontact block with at least one reciprocable operator extendingexteriorly thereof, a separate pushbutton operating assembly having alight transmitting lens, a molded insulating block immovably securedbetween said switch block and said operating as sembly and comprising anintegral portion extending into said assembly centrally thereof to whicha lamp base is secured, an impedance device in said block havingconnection with said lamp base, terminals extending exteriorly of saidblock and having connection interiorly thereof with said impedancedevice, and means extending through an opening in said block at one sideof said lamp base mounting portion affording an operating connectionbetween said operating assembly and the operator of said switch contactblock.

2. An illuminated pushbutton electric switch unit as specified in claim1, wherein said impedance device is a transformer molded in situ in saidinsulating block, wherein the reciprocable operator extends into theopening which extends through said block and wherein a push pin isprovided in said opening to afford an operating connection between saidoperating assembly and operator of said switch contact block.

3. An illuminated pushbutton electric switch as specified in claim 2,wherein said switch contact block contains at least two individualswitches with individual reciproca'ble operators, wherein saidreciprocable operators each extend into separate openings extendingthrough said molded insulating block and wherein each such openingcontains a push pin providing an individual operating connection betweeneach switch and said pushbutton operating assembly.

4. An assembly including a light module, a pushbutton operator, and apushbutton switch, and comprising a module including a body having afront end and a rear end and a light socket a! the front end,

an operator mounted on said front end of the body, and switch meansmounted on the rear end of the y,

said body having a passage extending therethrough from front to rear,

a pin in said passage and movable endwise thereof and engageable at itsforward end by the operator for movement endwise of the passage by theoperator, and

means on the switch engageable with the rear end of the pin for movementthereby when the pin: is moved by the operator.

5. A structure according to claim 4 wherein said body has a pair ofparallel laterally spaced bolt accommodating passages extendingtherethrough from front to rear:

bolts in said passages having externally threaded shanks at theirforward ends in threaded engagement with the operator and havinginternally threaded heads at their rear ends, and

additional bolts having externally lhreaded shanks at their forward endsin threaded engagement with the internally threaded heads and connectingthe switch means to the rear of the body.

References Cited The following references, cited by the Examiner, are ofrecord in the patented file of this patent or the original patent.UNITED STATES PATENTS 2,195,947 4/1940 Uhlrig 200-167 2,234,954 3/1941Bergman 200-167 2,591,336 4/1952 Bordelon 200-167 2,883,652 4/1959Ireland 340-252 2,914,705 11/1959 Krystyan et al 317-99 2,979,593 4/1961White 200-167 3,025,432 3/ 1962 Giegerich 317-99 3,028,587 4/1962Vaccaro 342-252 3,040,142 6/ 1962 Dietrich et a1 200-167 HERMAN O.JONES, Primary Examiner

